<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Room list</title>
    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css">
    <style type="text/css">
        .room-box {
            height:300px;
        }
        .room{
            font-size:40px;
            text-align: center;
            line-height:300px;
            overflow:hidden;
        }
    </style>
</head>
<body>

<div class="container">
    <div class="room-box">
        <div class="col-sm-4 room">
            <a href="room.html?room=1">房间1</a>
        </div>
        <div class="col-sm-4 room">
            <a href="room.html?room=2">房间2</a>
        </div>
        <div class="col-sm-4 room">
            <a href="room.html?room=3">房间3</a>
        </div>
    </div>
    <div class="room-box">
        <div class="col-sm-4 room">
            <a href="room.html?room=4">房间4</a>
        </div>
        <div class="col-sm-4 room">
            <a href="room.html?room=5">房间5</a>
        </div>
        <div class="col-sm-4 room">
            <a href="room.html?room=6">房间6</a>
        </div>
    </div>
</div>

</body>
</html>